Electric damper control



April 1947. H. c. HOLZ ELECTRIC DAMPER CONTROL Filed Aug. 1, 1945 2 Sheets-Sheet l M I g w F.

ATTD R N EYE April 29,1947.

H. C. HOLZ ELECTRIC DAMPER CONTROL Filed Aug. 1, 1945 2 Sheets-Sheet 2 I N VEN TOR.

flax/Ry (21x4 1 4 2 ATI'DR N EYS Patented Apr. 29, 1947 UNITED STATES PATENT OFFICE 4 Claims.

The invention relates to a control device, and more especially to a damper control apparatus for use in regulating pressure or boiler output.

The primary object of the invention is the provision of an apparatus of this character, wherein it is of electro-mechanical set-up, and automatically operated by the pressure from a boiler for controlling the damper thereof, and in this manner regulating the output of such boiler, to assure constant steam pressure therefrom.

Another object of the invention is the provision of an apparatus of this character, wherein the construction thereof is novel and unique in the arrangement of its parts, it being electrically controlled and thus economical to operate, and without a complicated set-up exteriorly of the boiler.

A further object of the invention is the provision of an apparatus of this character, which is simple in construction, thoroughly reliable and efficient in operation, strong, durable, possessed of few parts, thereby making it economical to repair and replacement of parts, automatic in the working thereof, positive in operation, and inexpensive to manufacture and install.

With these and other objects in view the invention consists in the features of construction, combination and arrangement of parts as will be hereinafter more fully described, illustrated in the accompanying drawings, which show the preferred embodiment of the invention and pointed out in the claims hereunto appended.

In the accompanying drawings:

Figure 1 is a top plan view, partly broken away, showing the apparatus constructed in accordance with the invention in association with a boiler damper.

Figure 2 is a side view, partly broken away.

Figure 3 is a sectional view taken on the line 3-3 of Figure 2 looking in the direction of the arrows.

Figure 4 is a sectional view taken on the line 4-4 of Figure 1 looking in the direction of the arrows.

Figure 5 is a fragmentary detail elevation showing a slight modification.

Similar reference characters indicate corresponding parts throughout the several views in the drawings.

Referring to the drawings in detail, A designates generally a portion of an air pressure conduitfroma fire box within a steam boiler, these being not shown, as the spirit of the invention contemplates its use to control any other boiler mechanism, such as a draft, blower engine, stoker engine or the like, and also instead of being op- 4 erated by pressure from the boiler, it could, if desired, be operated by changes in pressure in the fire box, or other variants in connection with the boiler, and in this instance, the operative is the pressure in the said fire box.

The conduit A is extended vertically within an oil font l0, which contains a determined quantity of oil II, and working within the latter is a fioat I 2 having a bell l3 movably telescoped onto the font Ill, as best seen in Figure 2 of the drawings. This bell i3 is provided with a filling spout l4 fitted with a removable cap l5, so that oil can be introduced into the said font. A

On a step l6 of a shelf 11 beneath the font l0 and to one side of the latter is a post I 8 which rises vertically above the plane of the said font and bell [3 for swingingly supporting a counterbalancing lever l9, which is provided with an eye yoke 20 intermeditate thereof for a clearance for the said post, the latter and the yoke being connected together by a horizontal pivot 2| for vertical swinging action of the lever l9. The shelf l1 is secured to a suitable support through the medium of brackets Ila.

Extending vertically centrally from the bell i3 is a hanger 22 to which is connected by a pivot 23 the lever [9, while at the outermost free end of the latter is fitted an adjustable weight 24 held in a set position by a set screw 25. Also connected to the hanger 22 at a point below the lever i9 is a secondary lever 26 which is also connected by a pivot 21 to the post H3 in parallelism with such lever IS. The lever 26 to the hanger 22 by a pivot 21a H In vertical relation to the post l8 and spaced therefrom is a guide stand 23 having a worm feed screw 29 working therein, the latter at its upper end through the medium of a chain39 has connection with a damper, not shown, for the regulation thereof and its control. This screw 23 has the spaced adjustable and stationary stops 3| and 32, respectively, while rotatably attached to the step I6 is a feed pulley wheel 33, which has threaded connection at its hub 34 with the screw 29 for the feeding thereof upwardly and downwardly to regulate the damper. The screw 29 is held against turning movement by vertical ribs 29a formed on the screw and slidably fitting within vertical guides 28a within the stand 28, as shown in Figure 3.

On the shelf I! is an electric motor 35 having its power shaft 35 fitted with a pulley 31 over which is trained an endless belt 33, which is also trained over one of a pair of reduction pulleys is connected 39 and 40, respectively, the other of these having an endless belt 4| trained thereover, and this belt being also trained over the wheel 33 for the driving of the latter.

Associated with the motor 35 is a magnetic reversing switch unit 42, which is supported on the shelf l1 and through an electric circuit system 43 having a strip switch 44 therein, is operated for the reversal of the motor. The switch 44 involves a throw blade 45 which is pivoted at 46 to the post 18 and also pivoted at 41 to a throw link 49, having pivoted thereto at 49 and 49a the trip arms 59 and respectively, the former being acted upon by the adjustable stop 3!, and the latter acted upon by the stationary stop 32 under the rise and fall of the screw 29, and such arms are rockingly attached on supports 52 and 52a above and below the stop l6.

Above the lever 19 and carried by the pivot 25 for the yoke 29 for disposition in the path of such lever 19 is a hand set weight 53, which can be manually thrown into one of three positions by a handle bar 54, one thrown position being shown by full lines in Figure 2 of the drawings, and the two other positions being shown by dotted lines in said Figure 2. The purpose of the weight 53 is to vary the activity of the lever l9 under variable pressures from the boiler, the pressure being trapped between oil level within the font I6 and the bell [3, as delivered thereto from the conduit A, as should be obvious. The weight 53 is secured to and between the swinging ends of arms 53a which are loosely connected to the pivot 2! of the lever l9. As shown, the weight is adapted to be swung into a neutral position directly above the pivot 2| or into an active position inwardly or outwardly of the pivot. When in said first active position, the weight 53 decreases the power of the weight 24 while when in said second active position, it adds to the power of the weight. The rod 54 is slidably mounted in guides 54a on the post 18 and has a forked upper end 5412 provided with fingers 540. The fingers 54 provide means which cooperate with one of the arms 53a during the manipulation of the rod 54 to move the weight in one of its three positions. The rod 54 is secured against accidental movement, to support the weight in its adjusted position, by a set screw 54d carried by a collar 54'e, which is secured to the shelf portion l6 and through which the rod passes.

In Figure 5 of the drawings, there is shown a slight modification, wherein the worm screw wheel 55 is a substitute for the wheel 33, and this wheel 55 meshes with a worm screw pinion 56, for the feeding of the screw 29, the pinion being driven from the motor 51, and through the use of the wheel 55 and pinion 56 the pulleys and belts, as before described, are dispensed with.

It should be obvious that the motor i the power source for moving the damper, and on the travel of the screw 29 in an upward direction, the said damper is moved to one position and reverse downward travel of such screw 29 the said damper is moved to the other position. It should be seen that the damper will always take a definite relative position with respect to the then existing boiler pressure and retain this position until the boiler pressure changes, the damper being automatically controlled through the use of the apparatu constituting the present invention.

The screw 29 is prevented from rotating in the (ill stand 28 by a guide pin 51, as best seen in Figure 1 of the drawings.

What is claimed is:

1. An apparatus of the kind described, comprising a feed screw for connection with a damper to change its position, an electric motor, driving connections between the motor and screw, an electric circuit system having reversing means for the motor, pressure operated means cooperating with the screw and circuit system to control the reversing means of the latter to have the screw change the position of the damper, an oil font and bell therefor included in the pressure operated means, and adjustable and stationary feed limit means on the screw.

2. An apparatus of the kind described, comprising a feed screw for connection with a damper to change its position, an electric motor, driving connections between the motor and screw, an electric circuit system having reversing means for the motor, pressure operated means cooperating with the screw and circuit system to control the reversing means of the latter to have the screw change the position of the damper, an oil font and bell therefor included in the pressure operated means, adjustable and stationary feed limit means on the screw, and means manually regulated for changing the activity of the pressure operated means.

3. An apparatus of the kind described, comprisin a feed screw for connection with a damper to change its position, an electric motor, driving connections between the motor and screw, an electric circuit system havin reversing means for the motor, pressure operated means cooperating with the screw and circuit system to control the reversing means of the latter to have the screw change the position of the damper, an oil font and bell therefor included in the pressure operated means, adjustable and stationary feed limit means on the screw, means manually regulated for changing the activity of the pressure operated means, and adjustable counter-balancing means for the bell.

4. An apparatus of the character described, comprising a feedscrew for connection with a damper to change its position, an electric motor, driving connections between the motor and the screw, an electric circuit system having reversing means for the motor, pressure operated means cooperating with the screw and circuit system to control the reversing means or the latter to have the screw change the osition of the damper, an oil font and bell therefor included in the pressure operated means, adjustable and stationary feed limit means on the screw, and manually regulated means including a fulcrumed balance arm for changing the activity of the pressure operatcd means, said last named means comprising a weight which may selectively be placed in inoperative position and on either side of the fulcrum.

HENRY CARL HOLZ.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,840,546 Uehling Jan. 12, 1932 2,076,616 Clarridge Apr. 13, 1937 1,658,577 Smoot Feb. 7, 1938 

